Ten injured, 86,000 lose power in hurricane

AT LEAST ten people have been injured as the formidable Hurricane Harvey wreaks a trail of destruction across Texas, tearing down roofs, knocking down power lines and uprooting trees.

A group was taken to a jail in Rockport for assessment and treatment after the roof of a senior housing complex collapsed, city manager Kevin Carruth told KIII-TV.

A high school partially caved in and the city's historic downtown area suffered heavy damage to vehicles and buildings as the fiercest hurricane to hit the US in more than a decade rampages through the state, with more than 86,000 losing power.

Around 128 people were evacuated from a Fairfield Inn in Rockport after the hotel suffered "severe damage," according to a National Weather Service report.

Department Chief Steve Sims said there were about 15 volunteer firefighters at the city's fire station waiting for conditions to improve enough for their vehicles to safely travel and to assess the damage to the city of about 10,000 people. "There's nothing we can do at this moment. We are anxious to get out there and make assessments, but we're hunkered down for now," he said.

The monster storm made landfall as a category 4 hurricane at 10pm Friday local time (1pm Saturday AEST), 48 kilometres northeast of Corpus Christi.

A tug boat worker who was out holding a drill ship to the dock during the storm tweeted: " Can't even begin to describe how bad it is right now."

The hurricane is expected to bring "catastrophic" flooding and major power outages as it makes its way across the state.

Texas Governor Greg Abbott warned that the system would be "a very major disaster," and the predictions drew fearful comparisons to Hurricane Katrina, one of the deadliest ever to strike the US.

Mayor Patrick Rios issued a chilling warning to residents ignoring the instruction of "get out and get out now" and refusing to leave the coastal town of Rockport. Rios told those who refused to evacuate with the majority of the town's 9500 population to "mark their arm with a sharpie, put their social security number" so they can be identified if found dead.

More than a metre of rain is expected to batter the US Gulf Coast, with the heaviest rainfall anticipated in San Antonio, Corpus Christi and Houston, according to a statement released by the Federal Emergency Management Agency (FEMA).

The hurricane was downgraded to category 3 as it made a second landfall on the northeastern shore of Copano Bay but the potential for serious damage once assessments can safely be made is severe.

Hundreds of thousands of people were urged to flee the path of the monster storm as Texas and Louisiana brace for massive inland flooding. Officials were expecting to see major flooding from two directions, with forecasters labelling it a "life-threatening storm".

US President Donald Trump signed a federal disaster declaration at the request of Texas Governor Greg Abbott in order to provide federal aid to those in the path of destruction as quickly as possible.